JPH0630850Y2 - Plasma CVD equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a plasma CVD apparatus for forming a film on a substrate moving in a vacuum processing chamber.

(Prior Art) Conventionally, as a substrate moving type plasma CVD apparatus, for example, as shown in FIG. 1, a cathode electrode c and an anode are provided in a vacuum processing chamber b evacuated from a vacuum exhaust port a, a. An electrode d is provided, and a high-frequency voltage is applied between both electrodes c, d to generate plasma by applying a high-frequency voltage, for example, from a gas inlet e provided on the plate surface of the cathode electrode c for film formation. It is known that a raw material gas is reacted and a film is formed on a substrate h which is heated by a heater f and moved in front of a cathode electrode c by a carrier g.

(Problems to be Solved by the Invention) In the conventional device, a strong plasma is generated on the plate surface of the cathode electrode c, but a weak plasma is generated or a plasma is not generated in a space outside the plate surface. . If film formation is performed by moving the substrate g in such a space where the plasma distribution is poor, there is a drawback that the film quality of the film formed on the substrate g becomes non-uniform in the film thickness direction.

In order to prevent this drawback, a deposition preventive plate is provided in front of the plate surface of the cathode electrode c and in front of and behind the traveling direction of the substrate g, and film formation is performed only when the substrate g moves to the strong plasma region in front of the cathode electrode c. I thought about doing the processing. However,
The provision of the deposition preventive plate can eliminate the disadvantage that the film quality is non-uniform, but it is not preferable because a disadvantage that the deposition rate is newly reduced occurs.

The present invention provides a plasma CVD capable of forming a thin film having a uniform film quality on a substrate by providing a deposition preventive plate and without reducing the film formation rate.
The purpose is to provide a device.

(Means for Solving the Problems) In the present invention, a cathode electrode and an anode electrode are provided in a vacuum processing chamber, and a raw material gas for film formation introduced into the vacuum processing chamber is caused to react by plasma discharge between the two electrodes. In a structure in which a film is formed on a substrate that moves in front of the cathode electrode, an adhesion preventive plate is provided between the cathode electrode and the moving path of the substrate so that the film is formed only in front of the cathode electrode. The above object is achieved by surrounding the front part of the cathode electrode with a perforated metal plate such as a metal mesh, punching metal, or foam metal. The hole diameter formed in the perforated metal plate is, for example, 1 to 2 mm, which allows the raw material gas for film formation to flow but does not leak plasma.

(Operation) When the vacuum processing chamber is evacuated to a vacuum, a raw material gas for film formation is introduced, and a high frequency voltage is applied between the cathode electrode and the anode electrode, plasma is generated in front of the plate surface of the cathode electrode, and the plasma is generated. The component of the raw material gas reacted by the above adheres in a thin film form to the plate surface of the heated substrate which moves in front of the cathode electrode. Since the periphery in front of the cathode electrode is surrounded by a perforated metal plate such as a metal mesh, plasma generated in front of the cathode electrode does not diffuse to the surroundings, the plasma density is increased, and The deposition rate of the reaction component does not decrease despite the provision of the deposition preventive plate, and a film having a uniform film thickness is formed on the substrate.

(Embodiment) An embodiment of the present invention will be described with reference to FIG. 2 in the drawing. In FIG. 1, reference numeral (1) is a vacuum processing chamber provided with vacuum exhaust ports (2) and (2), and (3) is A cathode electrode provided in the vacuum processing chamber (1),
(4) shows an anode electrode provided in front of the plate surface of the cathode electrode (3), the cathode electrode (3) is connected to a high frequency power source (not shown), and the anode electrode (4) is connected to ground. It Further, reference numeral (6) is a substrate which is held in front of the plate surface of the cathode electrode (3) by a substrate carrier (7) and moves along a movement path in the arrow direction, and (8) is the substrate (6). It is a heater that heats the back of the.

The above structure is also provided with a conventional substrate moving type plasma CVD apparatus, but in the present invention, the cathode electrode (3) with respect to the moving path between the cathode electrode (3) and the moving path of the substrate (6) is 3) is provided with a front and rear adhesion-preventing plate (10), and the front periphery of the cathode electrode (3) is surrounded by a perforated metal plate (11) such as a metal mesh, punching metal, or foam metal,
The plate surface of the cathode electrode (3) faces the space (12) surrounded by the perforated metal plate (11) and the plate surface of the substrate (6). The perforated metal plate (11) is preferably grounded. (13)
Is a gas inlet for introducing a raw material gas for film formation such as SiH ₄ gas provided on the plate surface of the cathode electrode (3), and (14) is between the cathode electrode (3) and the perforated metal plate (11). It is an insulating plate provided.

To explain the operation of the illustrated embodiment, the inside of the vacuum processing chamber (1) is evacuated by evacuation from the vacuum exhaust ports (2) and (2), and the source gas is introduced from the gas inlet port (13) so that the chamber ( When high frequency power is applied to the cathode electrode (3) after adjusting the pressure in 1), plasma is generated in front of the cathode electrode (3).
The plasma does not diffuse to the surroundings due to the perforated metal plate (11), the plasma density is increased, and from the gas inlet (13),
The raw material gas flowing through the small holes of the perforated metal plate to the exhaust ports (2) (2) causes a reaction and moves to the opening of the deposition-inhibitory plate (11) along the movement path. A thin film is attached to the plate surface of the substrate (6). Adhesion of the gas component to the substrate (6) is prevented by the adhesion-preventing plate (11).
Since it is performed in the opening area of the substrate and is not obliquely attached, rapid film formation is performed because a large amount of reaction occurs with a uniform plasma and strong plasma, and the deposition preventive plate (10 ) And without the perforated metal plate (11)
It was possible to improve the film formation rate by 20 to 60%.

The hole diameter of the perforated metal plate (11) is such that the raw material gas is circulated but the plasma does not leak out, for example, a small hole of 1 to 2 mm. The distance between the substrate carrier (7) and the deposition-inhibitory plate (10) is set to a few mm so that the plasma does not diffuse and the movement of the substrate (6) is not hindered.

(Effect of the Invention) As described above, according to the present invention, the deposition preventive plate is provided in front of the cathode electrode, and the periphery in front of the cathode electrode is surrounded by the perforated metal plate. It is possible to form a film with a uniform film thickness on the substrate, and the perforated metal plate prevents plasma from diffusing, allowing a large amount of reaction of the source gas to occur rapidly and improving the film formation rate. There is an effect that the film can be rapidly formed with a uniform film thickness.

[Brief description of drawings]

FIG. 1 is a cutaway side view of a substrate moving type plasma CVD apparatus provided with a deposition preventive plate, and FIG. 2 is a cutaway side view of an embodiment of the present invention. (1) …… Vacuum processing chamber, (3) …… Cathode electrode (4) …… Anode electrode, (6) …… Substrate (10) …… Prevention plate, (11) …… Perforated metal plate (13) ) ... Gas inlet

Claims (2)

[Scope of utility model registration request] 1. A substrate that moves in front of the cathode electrode by providing a cathode electrode and an anode electrode in a vacuum processing chamber, reacting a raw material gas for film formation introduced into the vacuum processing chamber by plasma discharge between the electrodes. In the case where a film is formed on the cathode electrode, a deposition preventive plate is provided between the cathode electrode and the moving path of the substrate so that the film is formed only in front of the cathode electrode, and the periphery in front of the cathode electrode is surrounded by metal. A plasma CVD apparatus characterized by being surrounded by a perforated metal plate such as a mesh, punching metal, or foam metal. 2. The plasma CVD according to claim 1, wherein the hole diameter formed in the perforated metal plate has a dimension that allows the flow of a raw material gas for film formation but does not allow plasma to leak. apparatus.